I think it may be worth noting that AVTS is not written by anybody connected with AAC or autism or special education or even disability, as far as I can tell. Whether that's relevant to the application's future is something we will only know in the future, but I have more faith in the integrity and the security for the future applications where the writers have a strong connection to disability in some way. Looking at the other applications by this company they're things like "Ringtones Uncensored" and other apps which use text-to-speech for amusement rather than utility. That doesn't mean the app is bad or that it won't be supported going forward, but personally it gives me much less faith in the app's long-term support.